The present invention relates to a printer and, more particularly, to a printer wherein the platen is integrally formed with the paper guide so as to form an assembly separate from the printer frame while the printing head is disposed on the printer frame, and the assembly is adjustably secured to the printer frame so that the proper relative positioning between the printing head and the platen is ensured without impairing the guiding operation of the paper guide while the assembly of the printer is made simple.
Heretofore, a thermal or electrically discharging type of printer has been proposed in which a printing head is reciprocally moved and the printing operation is effected during its forward movement with the printing head held so as to be urged against the platen to sandwich a paper sheet to be printed therebetween, while the printing head is held apart from the platen during its return movement so as to allow the paper sheet to be fed. Also, a printer has been proposed in which a plurality of printing heads are provided and all figures or characters are simultaneously printed by the printing heads.
In such a printer of the prior art, the paper guide and the platen have been independently secured to the printer frame. In the printing operation, the platen must be properly positioned with respect to the printing head or the printing head must strike the platen uniformly, in order to achieve proper printing or to obtain uniform density of the printed character. Therefore, in adjusting the position of the platen, the relative positioning between the platen and the paper guide is necessarily varied thereby deteriorating the paper guiding facility by the paper guide leading to jamming of the paper sheet. In order to avoid such deficiencies, a specially designed paper guide is required or the position of the paper guide per se must be readjusted corresponding to the adjustment of the platen. This makes the printer complicated or the assembly of the printer is made troublesome.
Further, a printer has been proposed in which the platen is moved toward and away from the stationary printing heads instead of the printing heads being moved. In this case, the paper guide is also arranged independently from the stationary printing heads. Therefore, the above described disadvantages can not be avoided.